A research team conducted a study showing that approximately 15% of all businessmen who wear ties wear them so tightly that they actually reduce blood flow to the brain, diminishing cerebral functions. At a board meeting of 20 businessmen, all of whom wear ties, what are the following probabilities? (Round your answers to three decimal places.)
(a) at least one tie is too tight
0.969

Correct: Your answer is correct.


(b) more than two ties are too tight

Incorrect: Your answer is incorrect.


(c) no tie is too tight

Incorrect: Your answer is incorrect.


(d) at least 18 ties are not too tight